直接甲醇燃料电池测试用温度控制系统

Temperature controlling system for direct methanol fuel cell testing

为了精确控制燃料电池阳极燃料的温度,搭建了直接甲醇燃料电池(DMFC)测试用温度控制系统。针对温度控制对象为定速流动的特点,设计了用于加热流动液体的特殊结构,即将不锈钢软管以双层跑道的布局紧密贴合于三层黄铜板之间,以延长液体在加热块中的流动时间,保证出口流动液体温度的精确控制。计算了不同内径的不锈钢软管最小管长和控制系统的最小加热功率。采用半导体制冷片为流体加热/制冷元件,设计制作了其功率驱动和换向电路。采用基于PID闭环控制的VC++程序设计方法实现了温度自动控制。实验结果表明:温度控制系统的平均升/降温速度为14℃/min,稳态温度控制示值误差<±2℃,能够满足DMFC恒定温度条件下实时测试的要求。

A testing system was established to control the liquid fuel temperature of Direct Methanol Fuel Cells（DMFCs）.In view of the temperature controlling for a certain flux liquid fuel,a heating block was fabricated,in which a flexible stainless steel pipe was laid with a double-runway for heating up the methanol solution.The minimum length of the pipe and the heating power of the controlling system were calculated.Furthermore,semiconductor-refrigerating chips were utilized to heat and cool the liquid flow during testing procedures and a power actuation circuit and a transition circuit according to the controlling requirements of the semiconductor-refrigerating chips and the testing system were also developed.On the basis of PID based closed-loop controller,the liquid temperature was controlled automatically and accuratelly by a software module written in Visual C＋＋.Experimental results show that the average cooling and heating velocity of the temperature controlling system is 14 ℃/min,and the precision of temperature controlling is better than ±2 ℃.It satisfies the system requirements of real time performance testing of DMFC.